The invention relates to improvements in and relating to milking machines, and is particularly concerned with apparatus for use in removing a teat-cup cluster from the animal being milked when milk flow has dropped to a predetermined level.
It is well recognised in dairy farming that it is important to remove the teat-cups from the cow being milked as soon as possible after the flow of milk from the udder diminishes to a certain level as the continued application of vacuum to the teats after the end point of milking has been reached is uneconomical and may be damaging to the udder. Furthermore, it is believed by some dairy farmers that overmilking increases the risk of mastitis. It is well known in modern milking parlours to utilize devices which visually indicate when the end point of milking has been reached. However, with such devices the teat cups must be removed manually and this imposes quite a strain on the operator handling a large number of cows in a " herring-bone" parlour, for example, as he must watch all of the indicators along the parlour and he must endeavour to remove the teat-cups from a large number of cows who may well cease milking about the same time. It is thus necessary in such parlours to employ a number of operators so as to ensure that milking proceeds efficiently and quickly. Means which automatically remove the teat-cup cluster from the cow when the end-point of milking has been reached increase the number of cows an operator can handle in a " herring-bone" type parlour and can enable a rotary parlour to be handled by one operator.
Automatic cluster removal systems are known in which photoelectric cells, conductivity cells or electronic microswitches, which are sensitive to milk flow, operate at the end of milking to actuate removal means, such as hydraulic or pneumatic rams, which withdraw the teat-cup cluster from beneath the cow. It has been found that these electronically operated systems are not reliable in use, and besides, are somewhat too complicated and expensive for the average farmer. Furthermore, they require an electrical supply at the milking stall which can be dangerous.
It is an object of the present invention to provide apparatus for removing a teat-cup cluster from an animal being milked including a milk flow rate sensing unit which reacts directly to the milk flow characteristic of each cow.